In this study, single-crystal gamma-MnO2 nanowires have been successfully synthesized at room temperature in the absence of catalysts or templates, the diameter was found to be ca. 10-20 nm and the characteristic lengths up to several micrometers. The crystal phase of nanowires was confirmed by XRD and TEM measurements. Further, a dissolution- condensation-recrystallization process was proposed for the formation of nanowires under the room temperature condition. (C) 2008 Elsevier B.V. All rights reserved.